Chelsea are still concerned that Michael Essien is weeks away from a return to the first team despite coming through a reserve team game on Monday night. The midfielder, whose absence since September with a cruciate knee injury has had a major effect on the team's season, is understood to be considered too much of a risk for a full return yet.

It was hoped that Essien, 26, who played 90 minutes and scored against Aston Villa reserves on Monday would be a contender for the squad against Coventry in the FA Cup quarter-finals on Saturday. However, the club's medical department are still reluctant to push Essien into a senior game. Joe Cole, who suffered the same injury against Southend United on 14 January, is out until next season.

It means that Hiddink will have to persist with John Obi Mikel in midfield: the 21-year-old was disappointing against Portsmouth on Tuesday night and was substituted before the hour. Essien's injury, sustained playing for Ghana in a World Cup qualifier in September, was originally thought to have ruled him out for all but the very end of the season. While he has recovered quickly, the club are worried that he is still vulnerable to other problems.

As for Hiddink, who has led Chelsea out of the wilderness with four straight victories since he took over on 16 February, it emerged yesterday that he was the beneficiary of a major stroke of luck against Portsmouth. The Chelsea manager was just about to substitute goalscorer Didier Drogba before he hit the winner on 78 minutes at Fratton Park.

Hiddink had told his assistant, Ray Wilkins, to prepare the 19-year-old Franco Di Santo to come on for Drogba and, although Chelsea went as far as notifying the fourth official, they changed their mind before he came to display the number. When Drogba scored, and ran towards the dugouts, Wilkins stood in front of Di Santo and told him to put his tracksuit back on. By time the play kicked off again the Argentine was back on the bench.

However, Hiddink might have felt privately about Drogba's performance before his winning goal, he needs him more than ever. Nicolas Anelka, who has a bruised toe, will miss the game on Saturday in order for him to be fit to face Juventus on Tuesday.

Petr Cech said after Tuesday's win that the turning point for Chelsea's season was during their FA Cup fifth round win over Watford when, he said, they came back from the dead after going one goal down. "We overcame that moment and won the game and since then our confidence has grown," he said. "It was classic Chelsea. We were nearly dead but we came back and won and that tells you that, if we keep playing and believing, then the spirit of the team is always there and we have kept building on that.

"We know we have to win all of our games to have a chance. United know destiny is with them because if they win every game they will be champions. We will try to make sure that if one day they have a bad day and lose some points we will close the gap."